AB0183 DEVELOPMENT AND VALIDATION OF THE PLACEBO SENSITIVITY QUESTIONNAIRE (PSQ): CAN THE PSQ PREDICT PLACEBO ANALGESIA RESPONSIVENESS?
Authors: E. Camerone, G. Tosi, M. Di Magro, D. Romano
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> People respond to placebo to different degrees, and some do not respond at all (Frisaldi et al., 2018). Several studies investigated whether there are psychological aspects that predict these differences, but the results remain heterogeneous (Horing et al., 2014; Kern et al., 2020) <h3>Objectives</h3> Here, we develop and validate the Placebo Sensitivity Questionnaire (PSQ), an instrument that measures behaviors potentially related to placebo responsiveness. The idea is to treat placebo as a personality trait, with its own dimensions and its set of marker behaviours, instead of a phenomenon determined by multiple personality traits as it has been done up to now. <h3>Methods</h3> 330 individuals completed the initial version of the PSQ along with 9 additional scales measuring psychological traits associated with placebo responsiveness. These data were used to reduce the dimension of the PSQ, identifying a shorter set of predictive items, and to bring evidence of construct validity. A second experiment, currently ongoing, tests the predictive validity of the PSQ using a classic placebo analgesia experimental paradigm. Here, healthy volunteers are administered a placebo cream, presented as a potent analgesic, and receive noxious stimulations by means of thermal stimulation. <h3>Results</h3> Principal component analysis revealed a 3-factor structure – Symptoms Exaggeration, Seek for Support, Alternative Medicine Beliefs - and the number of items was reduced from 40 to 19. Construct validity indicated that the PSQ correlates with most of the scales previously associated with placebo responsiveness. For the predictive validity study, which is in due course at the time of this abstract submission, we hypothesise that the PSQ will be successful in discriminating a priori placebo sensitivity and non-responders. <h3>Conclusion</h3> The PSQ has the potential to become an important tool for researchers and clinicians working with pain, moving us a step forward toward personalised pain management. <h3>References</h3> [1] Frisaldi, E., Shaibani, A., &amp; Benedetti, F. (2018). Placebo responders and nonresponders: what's new? <i>Pain Management</i>, <i>8</i>(6), 405–408. https://doi.org/10.2217/pmt-2018-0054 [2] Horing, B., Weimer, K., Muth, E. R., &amp; Enck, P. (2014). Prediction of placebo responses: a systematic review of the literature. <i>Frontiers in Psychology</i>, <i>5</i>. https://doi.org/10.3389/fpsyg.2014.01079 [3] Kern, A., Kramm, C., Witt, C. M., &amp; Barth, J. (2020). The influence of personality traits on the placebo/nocebo response. <i>Journal of Psychosomatic Research</i>, <i>128</i>, 109866. https://doi.org/10.1016/j.jpsychores.2019.109866 <h3>Acknowledgements</h3> I am grateful to all of those with whom I have had the pleasure to work during this project. First, I thank my supervisor, Daniele Romano, for his guidance and supervision. I thank Giorgia Tosi, co-author of this study, for her analysis skills and for the brainstorming. I also thank Marcello Di Magro, who helped with data collection as part of his thesis. More generally, I thank all the members of our research team for their ongoing support and feedback during our weekly Lab meetings. <h3>Disclosure of Interests</h3> None Declared.